an evening when you go to various places and enjoy entertainment such as dancing, eating in a restaurant, or drinking in a bar

UK Let's have/go for a night on the town to celebrate. 让我们狂欢一夜以示庆祝吧。

US We were out for a night on the town to celebrate Dee's graduation. 为了庆祝迪伊毕业，我们晚上外出狂欢了一夜。